Apple has made its first acquisition of 2016, and it’s another company specializing in artificial intelligence. The Cupertino-based firm has bought San Deigo startupEmotient Inc. for an undisclosed sum, according to a report from the Wall Street Journal.

Emotient’s AI technology is used to determine a person’s emotions just by analyzing their facial expressions. It’s primarily sold to advertisers and marketers who use it to assess consumers reactions to ads and products. The tech has also been tested by doctors to interpret signs of pain in patients who are unable to express themselves.

Emotient had previously been tested on Google Glass as a way to find out what emotions people around you were feeling by analyzing their faces. The camera on the device was used to identify and process facial expressions and provide an emotional read-out on the small screen.

It’s not clear what plans Apple has for Emotient’s technology. It could be used on its own iAds platform, photo apps, or even implemented into FaceTime. The company rolled out its usual generic statement after the acquisition: “ [Apple] buys smaller technology companies from time to time, and we generally do not discuss our purpose or plans.”

Apple has acquired a series of companies over the last 12 months that have a focus on AI systems. In October last year, the iPhone maker bought Perceptio, a small startup company specializing in technology that lets companies run artificial intelligence systems on smartphones without needing to share much user data.

Apple has also bought VocallQ – a firm that specializes in natural language processing as it applies to automobiles – and mapping data analytics startup Mapsense. In November 2015, the company confirmed it had bought Faceshift, a Swiss startup that uses real-time motion capture technology to captures a person’s facial expressions in order to create CGI avatars and other figures.

Assuming this isn’t all part of a plan to build Skynet, these acquisitions suggest that AI will play an even bigger role in Apple’s future products.